DC power control to maximize battery charging time

• US 9,007,024 B2
• Filed: 05/28/2008
• Issued: 04/14/2015
• Est. Priority Date: 05/28/2008
• Status: Expired due to Fees

• Current Assignee: American Reliance Incorporated (Ametek Incorporated)
• Original Assignee: American Reliance Incorporated (Ametek Incorporated)
• Inventors: Li, Fu Yu, Chen, Kalvin
• Primary Examiner(s): Tso, Edward
• Assistant Examiner(s): TORRES RUIZ, JOHALI ALEJANDRA
• Application Number:
  US12/128,408
• Publication Number:
  US 20090295330A1
• Time in Patent Office: 2,512 Days
• Field of Search: 320/124
• US Class Current: 320/124
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0025 Sequential battery discharge in systems with a plurality of batteries

Abstract

Systems and methods are provided for managing the batteries and the power source as a single combined output to power the load, allowing the system to use power source with reduced maximum power output, reducing system cost and complexity. Furthermore, the switch matrix controller efficiently and dynamically manages the internal power transfer to minimize the charging/discharging cycle of the batteries while ensuring that the power source and the batteries meet changing load power demand. Finally, maximizing charging time and having independent control of each battery increase power efficiency, prolong the operational life of the battery, and increase overall system life.

Claims

1. A switch matrix power control system comprising:

a plurality of charge switches between a power source and a plurality of batteries;

a charge control circuit coupled to the plurality of charge switches, wherein the plurality of charge switches is adapted to selectively transfer power from the power source to a corresponding battery from the plurality of batteries;

a plurality of discharge switches between the plurality of batteries and a load;

a discharge control circuit coupled to the plurality of discharge switches, wherein the plurality of discharge switches is adapted to selectively transfer power from one or more of the batteries to the load in a fixed order of discharge, wherein each of the batteries starts the transfer of power based on the fixed order independent of a voltage of each of the batteries, and wherein the batteries are restored to a charging state to receive power from the power source through the plurality of charge switches in a fixed order of charge that is reversed from the fixed order of discharge such that the fixed order of charge is also independent of the voltage of each of the batteries;

a reset circuit coupled to the charge control circuit and the discharge control circuit to generate a periodic reset pulse to periodically open the plurality of discharge switches to stop the discharge from any of the batteries to the load and to periodically close the plurality of charge switches to restore all the batteries to the charging state, wherein after the periodic reset pulse the discharge control circuit determines whether to re-close any of the discharge switches;

a direct output switch between the power source and the load; and

an output control circuit coupled to the direct output switch to selectively transfer power from the power source to the load.

2. The switch matrix power control system of claim 1, wherein the transfer of power from one or more of the batteries to the load is combinable with the transfer of power from the power source to the load.

3. The switch matrix power control system of claim 1, further comprising a plurality of voltage comparators and a plurality of voltage references coupled to the discharge control circuit, wherein one of the voltage comparators compares a voltage at the load against one of the voltage references for starting the transfer of power from one of the batteries to the load, and wherein each of the voltage references is at a different level to correspond to the fixed order of discharge.

4. The switch matrix power control system of claim 1, wherein the charge switch and the discharge switch corresponding to one of the batteries are in the opposite state.

5. The switch matrix power control system of claim 1, further comprising:

a plurality of first voltage comparators and a plurality of first voltage references coupled to the discharge control circuit, wherein one of the voltage comparators compares a voltage at the load against one of the first voltage references for terminating the transfer of power from one of the batteries to the load;

a second voltage comparator and a second voltage reference coupled to the charge control circuit to compare a voltage at the power source against the second voltage reference for protecting the plurality of batteries against excessively high power source voltage; and

a third voltage comparator and a third voltage reference coupled to the output control circuit to compare a voltage at the power source against the third voltage reference for protecting the load against excessively high power source voltage.

6. A power control system comprising:

a first switch coupled between a power source and a load;

a plurality of charging switches coupled between the power source and a plurality of batteries to charge one or more of the batteries from the power source;

a plurality of discharging switches coupled between the load and the plurality of batteries;

a first detector coupled to the load to determine whether power supplied to the load is from the power source, one or more of the batteries, or a combination of the power source and one or more of the batteries, wherein the one or more of the batteries discharge through one or more of the discharging switches in a fixed order of discharge independent of a voltage of each of the one or more batteries, and wherein the batteries are restored to be charged from the power source through the plurality of charging switches in a fixed order of charge that is reversed from the fixed order of discharge such that the fixed order of charge is also independent of the voltage of each of the one or more batteries, and

a reset circuit to generate a periodic reset pulse to periodically open the plurality of discharging switches to stop the discharge from any of the batteries to the load and to periodically close the plurality of charging switches to restore all the batteries to be charged from the power source, wherein after the periodic reset pulse the first detector determines whether to re-close any of the discharging switches.

7. The system of claim 6, further comprising a second detector coupled to the power source to determine whether power from the power source is supplied to one or more of the batteries through one or more of the charging switches, the load, or a combination of the load and one or more of the batteries.

8. The system of claim 6, further comprising:

a charge control circuit coupled between the plurality of charging switches and the power source to independently control each of the charging switches;

a discharge control circuit coupled between the plurality of discharging switches and the load to independently control each of the discharging switches; and

an output control circuit coupled between the first switch and the power source to control the first switch.

9. The system of claim 8, wherein the reset circuit is coupled between the charge and discharge control circuits.

10. The system of claim 6, wherein the charging switch and the discharging switch for a corresponding battery from the plurality of batteries are in opposite states.

11. A method of managing power to a load comprising:

determining a voltage required by the load;

supplying the voltage from a power source if the power source is sufficient to supply the voltage;

supplying the voltage from the power source and one or more batteries of a plurality of batteries if the power source is insufficient to supply the voltage, wherein the plurality of batteries has a fixed order of discharge independent of a voltage of each of the batteries, wherein a battery from the plurality of batteries with a later order of discharge starts supplying power to the load if power from all batteries with earlier order of discharge are insufficient to supply the voltage, and wherein the plurality of batteries is restored to a charging state to receive power from the power source in a fixed order of charge that is reversed from the fixed order of discharge if the power from the plurality of batteries is sufficient to supply the voltage such that the fixed order of charge is also independent of the voltage of each of the batteries; and

periodically stopping the discharge from any of the batteries to the load, periodically restoring all the batteries to the charging state, and determining whether to resume supplying power from one or more batteries to the load.

12. The method of claim 11, further comprising:

determining a voltage from the power source; and

pulse charging the plurality of batteries from the power source if the voltage from the power source is higher than a reference voltage for the plurality of batteries.

13. The method of claim 11, further comprising:

determining a voltage from the load; and

terminating the supplying of voltage from the one or more batteries if the voltage from the load is below a reference voltage for the plurality of batteries.

14. The method of claim 11, further comprising:

determining a voltage from the power source; and

pulsing the voltage from the power source to the load if the voltage from the power source is higher than a reference voltage.

15. The method of claim 11, further comprising charging one or more of the batteries from the power source when power from the one or more batteries is not needed for the load, wherein when charging a plurality of the batteries, proportionately more power is distributed to a charging battery having a lower voltage than a charging battery having a higher voltage.